Multiple print engine system with selectively distributed ripped pages

ABSTRACT

A multiple print engine configuration allows a plurality of workstations ( 10 ) to create individual print jobs and then transfer them to a distributing processor ( 14 ). The distributing processor ( 14 ) is operable to spool the jobs in a print spooler ( 20 ) and then perform a software RIP on the print jobs. The RIP process divides the jobs into multiple individual jobs which are stored in the page buffer ( 24 ). An image task manager ( 26 ) in conjunction with an engine manager ( 28 ) are then operable to selectively distribute the pages to multiple print engines ( 16 ). They are distributed in such a manner that they are placed in the output bins ( 40 ) in the order that the pages were received in the print jobs.

This application is related to U.S. Pat. No. 5,596,416, and entitled“Multiple Printer Module Electrophotographic Printing Device”.

TECHNICAL FIELD OF THE INVENTION

The present invention pertains in general to electrophotographicprinters and, more particularly, to a plurality of print enginesarranged in parallel to process print jobs in a parallel manner.

BACKGROUND OF THE INVENTION

Electrophotographic print engines have been utilized with both printersand copiers. In a printer, the print engine is typically interfaced witha computer to select and organize fonts or bit map the images. In acopier application, the print engine is interfaced with an input devicethat scans the image onto the photoconductor drum of the print engine.However, a CCD device could also be utilized in this application in theform of a CCD scanner. In either of the applications, a conventionalprint engine for a monochrome process would typically feed a singlesheet of paper and pass it by the photoconductor drum for an imagetransfer process and then pass it to a fuser. Thereafter, the completedsheet will be output. Multiple copy print jobs will sequentially feedthe paper in a serial manner. The speed of the printer is a function ofthe speed at which the image can be created, the speed at which theimage can be transferred to the paper and the speed of the fuser. Asincreased output is required, the speed of each of these elements mustbe increased.

In a monochrome process, only one transfer operation is required.However, in a multipass color process, multiple images must besuperimposed on one another on the sheet of paper in a direct transfersystem, thus requiring multiple passes of the paper or image carrierthrough the print engine. In a double transfer system, the image isdisposed on an intermediate drum and then the composite imagetransferred to the paper or image carrier. In a multiple print job on adirect transfer system, this requires each sheet of paper to be printedin a serial manner by passing it through the print engine. For eitherthe monochrome process or the color process, a conventional serial feedprint engine has the output thereof defined by the speed of the inputdevice and the speed of the print engine itself.

One technique that has been utilized to increase throughput is a tandemprint engine. In a tandem print engine, multiple colors can be disposedon the sheet of paper or the image carrier at different stations thatare disposed in serial configuration. In this manner, the speed is thesame for one, two, three or four color printing.

SUMMARY OF THE INVENTION

The present invention disclosed and claimed herein comprises a multipleprint engine system. The system includes at least one workstation forgenerating one or more print jobs having a plurality of copiesassociated with each print job. A RIP engines is operable to receive theprint job and parse it into separate pages in association with the printjob. These are then disposed in a page buffer. A plurality of printersare then provided which are each accessible in parallel. A processor isoperable to select pages from the page buffer and output them to selectones of the printers in a predetermined order.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference is now made to the following descriptiontaken in conjunction with the accompanying Drawings in which:

FIG. 1 illustrates an overall block diagram of the present invention;

FIG. 2 illustrates a more detailed block diagram of the presentinvention;

FIGS. 3a, 3 b and 3 c illustrate three general processingconfigurations;

FIG. 4 illustrates a cutaway side view of a three module multiple printengine operated in accordance with the present invention;

FIG. 5 illustrates a flowchart illustrating the parsing operation;

FIG. 6 illustrates a flowchart for the duplex operation for a face upoutput; and

FIG. 7 illustrates a flowchart for the duplex operation for a face downoutput.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, there is illustrated a block diagram of theoverall operation of the present invention. A plurality of workstations10 are provided, which workstations 10 comprise general personalcomputers or other terminals that allow a user to create print jobs.Each of the workstations is networked through a network interface 12,which is a conventional type of general network interface such as anEthernet® network interface. This allows each workstation 10 to send itsprint job to a central processor 14, which processor is operable toprocess the print jobs in accordance with the system of the presentinvention and distribute these print jobs to multiple print engines 16.As will be described hereinbelow, the processor 14 is operable todisassemble the print job, parse the print job into different pages anddistribute the parsed pages in a predetermined manner in accordance withthe present invention. It should be understood that a print job,although initiated as a series of pages, is sent as a single job to aprinter. Typically, printers receive the print job in a conventionalmanner, which is a string of digits and the printers determine whetherthe codes are for an end of page command, etc. However, most printoperations within a given workstation 10 are designed such that theprint job is to be sent to a single printer and, therefore, the codesare all “bundled” in a common string or job. As will be describedhereinbelow, in order for the pages to be parsed, it is important tofirst determine what the beginning and the end of a print job is, thendetermine what printer to send that distinct and separate page to, inaccordance with the system of the present invention.

Referring now to FIG. 2, there is illustrated a more detailed blockdiagram of the operation of the processor and the parsing operation fordistributing the parsed pages to the various print engines 16. The jobis received in a serial. manner, and is “spooled” in a print spooler 20.This is then passed to a software RIP engine 22 which is operable toessentially decode the print string that is received from the printspooler 20. This effectively divides each print job into pages. Thesepages are then stored in page buffers 24. Each page in the page bufferessentially constitutes a single print job, such that any print jobreceived from the workstations 10 will then be parsed into a multipleprint job file. For example, if a thirty page document were to be sent,this would be sent as a single print job, which would be encoded assuch. The software RIP engine 22 is then operable to divide this intothirty separate print jobs.

Once the pages are stored in the page buffer 24, then the pages are sentto an image task manager 26 to determine how to organize the pages. Thisoperates in conjunction with an engine manager 28 to determine which ofthe print engines 16 the job is to be passed to. In order to effectivelyincrease the throughput from the engine manager 28, there are providedinterface circuits 32 which are referred to as Peripheral ConnectInterface (PCI) adaptors. Each print engine 16 has a PCI 32 associatedtherewith. Therefore, the engine manager 28 interfaces with the PCIs 32through a parallel bus 36, such that data can be transferred thereto ata fairly high data rate, which is the bus transfer data rate of theprocessor 14. The PCIs 32 therefore provide an increased rate oftransfer to the print engine 16. The print engines 16 then place theiroutput into a separate output bin 40 for each of the print engines 16.

As will be described hereinbelow, the image task manager 26 is operableto arrange the copies such that they can be placed in the output bins 40in a predetermined order. For example, if there were two print engines,each with a 100 sheet paper supply and four print jobs of 50 copies eachwere to be sent to the printers and the workstation 10, the system ofthe present invention would parse these print jobs such that the firsttwo print jobs went to the first print engine and the second two printjobs went to the second print engine. If, alternatively, the two printengines with the one hundred sheet paper supplies handled two printjobs, one at a 150 sheets and one at 50 sheets, then the first printengine would receive the first 100 sheets from the first print job, thesecond print engine would receive the first 50 sheets of the first printjob and the second 50 sheets of the second print job. However, theywould be sent to the printer in such a manner that when the paper outputtrays were unloaded and stacked together, the jobs would be arranged inthe appropriate manner. Therefore, even though there are multipleprinters, to the user they appear as a virtual single printer. Alldecision making is made in the processor 14.

Referring now to FIGS. 3a-3 c, there are illustrated the variousconfigurations illustrating the transfer of data between an input and aprint engine. In FIG. 3a, there is illustrated a general diagram of asoftware RIP processor 42, which is operable to generate the datanecessary to transfer to a print engine 46. However, this is effectedover a conventional parallel port 48. In this configuration, thesoftware RIP processor 42 is relatively fast, whereas the print engine46 is relatively slow. Of the time to print, three percent of that timeis occupied by the operation of print engine 46, seventy percent isoccupied by the software RIP processor 42 and twenty-seven percent isoccupied by transferring the data from the processor 42 to the printengine 46. Therefore, the parallel port 48 becomes a key factor in theprinting time. In FIG. 3b, software RIP processor 42 is connected to theprint engine 16 via a PCI 50. In this configuration, ninety-five percentof the print time is occupied by the software RIP processor 42, threepercent by the print engine 16 and five percent by the PCI 50.Therefore, by reducing the transfer time from the processor 42 to theprint engine 16, an increase in speed has been seen. In FIG. 3c, thereis illustrated a fairly conventional system wherein a processor 52 isprovided, which can be a conventional PC for assembling the print job ina conventional manner and transferring it via a parallel port 54 to anengine 58, which is a conventional print engine having an internal RIP60 associated with a marking engine 62. The processor 52 is relativelyfast, and it occupies virtually no time. Seventeen percent of the printtime is taken passing the data to the RIP 60 through the parallel port54, whereas eighty percent of the print time is occupied with the RIP 60and only three percent by the marking engine 62.

Referring now to FIG. 4, there is illustrated a cutaway side view of athree print engine module parallel printer which includes three printengines 136, 138 and 40, all stacked one on top of the other. Each ofthe engines 136-140 is a multi-pass engine and includes a transfer drum142 and a photoconductor drum 144. The photoconductor drum 144 rotatesin a counterclockwise direction and is pressed against the transfer drum142 to form a nip 146 therebetween. The photoconductor drum 144 isoperable to have the surface thereof charged with a corona 148 and thenan imaging device 150 is provided for generating a latent image on thecharged surface of the photoconductor drum 144. The undeveloped latentimage is then passed by four developing stations, three color developingstations, 152, 154 and 156 for the colors yellow, magenta and cyan, anda black and white developing station 158. The color developing stations152, 154 and 156 each have a respective toner cartridge 160, 162 and 164associated therewith. The black and white developing station 158 has ablack and white toner cartridge 166 associated therewith. Although notdescribed hereinbelow, each of the developing stations 152-168 and tonercartridges 160-166 can be removed as individual modules for maintenancethereof.

During the print operation, the photoconductor drum 144 is rotated andthe surface thereof charged by the corona 148. An undeveloped latentimage is then formed on the surface of the photoconductor drum 144 andthen passed under the developing stations 150-158. In a multi-passoperation, the latent image is generated and only one color at a timeutilized in the developing process for the latent image. This latentimage is then passed through the nip 146 and transferred to an imagecarrier, such as paper, which is disposed on the surface of the transferdrum 142. Thereafter, the surface of the drum 144 is passed under acleaning station 168, which is operable to remove any excess tonerparticles which were not passed over to the transfer drum 142 during thetransfer operation and also discharges the surface of the drum 144. Thesystem then begins generation of another latent image, either for adifferent color on the same sheet of paper or the first color on adifferent sheet of paper.

In the color operation, multiple passes must be made such that the imagecarrier, i.e., paper, remains on the surface of the transfer drum 142for the multiple passes. In the first pass, the first latent image istransferred to the surface of the transfer image carrier and then theimage carrier maintained on the transfer drum 142. The next latent imageof the next color is superimposed on the first latent image, it beingnoted that the registration is important. This registration is providedby the mechanical alignment of the various drums, drive mechanisms, etc.Thereafter, the third color latent image is disposed on the imagecarrier followed by the fourth color latent image.

After the last color latent image is disposed on the image carrier inthe color process, a picker mechanism 172 comes down on the surface ofthe transfer drum 142 in order to lift up the edge of the image carrieror paper. This is then fed to a fuser mechanism 174.

The image carrier is typically comprised of a predetermined weightpaper. The transfer drum 142 utilizes electrostatic gripping for thepurpose of adhering the paper to the surface of the transfer drum 142for multiple passes. This therefore utilizes some type of chargingmechanism for charging the surface of the drum 142 at an attachmentpoint 176 where the paper is fed onto the surface of the transfer drum142. The transfer drum 142 is, in the preferred embodiment, manufacturedfrom a controlled resistivity type material that is disposed over analuminum support layer which is a hollow cylindrical member. A voltagesupply is provided that provides a uniform application of voltage fromthe voltage supply to the underside of the resilient layer that isdisposed over the surface of the aluminum support member. This resilientlayer is fabricated from a carbon filled elastomer or material such asbutadaiene acrylonitorile, which has a thickness of approximately 3 mm.Overlying this resilient layer is a controlled resistivity layer whichis composed of a thin dielectric layer of material at a thickness ofbetween 50 and 100 microns. This controlled resistivity layer has anon-linear relationship between the discharge (or relaxation) pointtying and the applied voltage such that, as the voltage increases, thedischarge time changes as a function thereof. The paper is then disposedover the surface of the drum. The construction of this drum is describedin U.S. patent application Ser. No. 08/141,273, filed Oct. 22, 1993, andentitled, “Buried Electrode Drum for an Electrophotographic Print Enginewith a Controlled Resistivity Layer”, which is a continuation-in-part ofU.S. patent application Ser. No. 07/954,786, filed Sep. 30, 1992, andentitled, “Buried Electrode Drum for an Electrophotographic PrintEngine”, which U.S. patent application Ser. No. 07/954,786, isincorporated herein by reference.

The paper is retrieved from one of two paper supply bins 178 or 180. Thepaper supply bin 178 contains one type of paper, typically 8½″×11″paper, and the paper bin 180 contains another type of paper, typically8½″×14″ paper. The paper bin 178 has the paper stored therein selectedby a first gripping roller 182, which is then fed along a paper path 180into a nip 182 between two rollers and then to a nip 184 between tworollers. This is then fed to a paper path 186 to feed into a nip 188between two rollers. The paper in the nip 188 is then fed into a nipformed between two precurl rollers 190 and 192, which have differentdurometers to cause the paper to have a curl bias applied thereto in thedirection of the curvature of rotation of the transfer drum 142. Theoperation of the pre-curl rollers is described in detail in U.S. Pat.No. 5,398,107, issued Mar. 14, 1995, and entitled, “Apparatus forBiasing the Curvature of an Image Carrier on a Transfer Drum”. The paperfrom the bin 180 is extracted by a gripping roller 189 and pushed alonga paper path 191 to the nip 188 and therefrom to the pre-curl rollers190 and 192.

The paper is fed from the nip between the two pre-curl rollers 190 and192 at the attachment point 176. At the attachment point 176, anattachment electrode roller 194 is provided which is operable to operateon a cam mechanism (not shown) to urge the roller 194 against thesurface of the drum 142 to form the attachment nip 176. This is doneduring the initial attachment of the paper to the drum 142. Typically,this attachment electrode roller 194 is connected to ground. The surfaceof the drum 142 is charged to a positive voltage of between 800-1,000volts. The voltage is disposed on the surface of the drum 142 by apositive electrode roller 196 that contacts the surface of the drum 142at a point proximate to the photoconductor drum 144. Since the electrode194 is grounded, the voltage will decrease along the surface thereofuntil a lower voltage is present at the attachment point 176. When thepaper reaches the transfer nip 146, the portion of the surface of thephotoconductor drum 144 in the nip 146 has a potential thereof reducedto ground such that the charged particles will be attracted from thesurface of the photoconductor drum 144 to the surface of the paper onthe drum 142.

For a multiple pass operation, the attachment electrode 176 will bepulled outward from the drum and the paper allowed to remain on the drumand go through the transfer nip 146 for another pass. When the finalpass has been achieved at the transfer nip 146, the picker 172 is swungdown onto the surface of the drum 142 to direct the paper on the surfaceof the drum 142 to the fuser 174. A discharge electrode 198 is thenswung down into contact with the drum 142 to provide a dischargeoperation before the surface of the drum enters the nip 176 for the nextpaper attachment process.

When the paper is fed into the fuser 174, it is passed into a nipbetween two rollers 200 and 202, both of which have differentdurometers. Typically, there is one roller that is formed from ametallic material and one roller that is formed of a soft material. Therollers are oriented with the roller 200 having the smaller durometer,such that a reverse bias curl will be applied to the paper that is theopposite direction of the curvature of the drum 142. This will removethe curvature added to the paper. One of the rollers 200 is heated suchthat the transferred image is “fused”. The paper is then fed into apaper path 204 by a pair of rollers 206. The paper path 204 is fed to aset of output rollers 208, which feed bins 210, 212 and 214 for each ofthe printers 136, 138 and 140. Again, these are conventional printengines, although the speeds of the print engines may be different.

Referring now to FIG. 5, there is illustrated a flowchart depicting theoperation of the present invention. For this description, the followingterms are defined:

N=number of pages in a single document

M=copies

E=number of engines

P=number of pages

i=the engine number.

The flowchart is initiated at a start block 230 and then proceeds to adecision block 232. A decision block 232 multiples the number of pages Nby the number of copies M and determines whether this number if greaterthan or equal to the number of engines. If not, then the program flowsalong a “N” path to a function block 234 to utilize only a single enginefor the print job. However, if the number is greater than the number ofengines, then the program proceeds along the “Y” path to a decisionblock 236 to determine the number of copies M is greater than the numberof engines E. If not, the program flows along a path “N” to a decisionblock 238 to determine if the number of pages in a single document “N”is greater than or equal to the number of engines. If not, the programwill flow along a “N” path to a function block 240 to utilize the only Mengines with the ith copy in the ith engine. Therefore, if there are tenengines and only five copies, then the fifth copy of a job will be inthis ith engine. If, however, the number of copies in a single documentis greater than the number of engines, then the program will flow alonga “Y” path to a function block 242 wherein the copies will bedistributed in accordance with the equation: $\begin{matrix}{p = \frac{N \times M}{E}} & (1)\end{matrix}$

If it was determined in the decision block 236 that the number of copiesM was greater than the number of engines with the number of copies timesthe number of pages in a single document also being greater than thenumber of engines, then the program flows along the “Y” path fromdecision block 236 to a decision block 244 to distribute copies. Theseare distributed in accordance with the algorithms illustrated in FIG. 5with respect to four of the engines E₁, E₂, E₃ and E₄. E₁, E₂ and E₃ arealso associated with function blocks 246, 248 and 250, each operating inaccordance with the above equation, one associated with function block242. However, E₄ will flow to a function block 256 wherein thedistribution will be as follows:

P ₄ =N×M−(P ₁)+P ₂+2P ₃)  (2)

Referring now to FIG. 6, there is illustrated a flowchart depicting theoperation for a duplex print job. In the flowchart of FIG. 6, a face upoutput is considered which is initiated at a block 260. The functionblock then flows to a decision block 262 to determine if the value of Nis even. If so, the program flows to a function block 264 to print thejobs N−2, N−4 . . . , 2. The program then flows to a decision block 266,which determines whether the value of N is odd. However, if N was odd atdecision block 266, the program would flow along the “N” path to theoutput of the decision block 266 and then to a function block 268 toprint the N+1 copies and blank copies and then print the N−1, N−3, . . .1 pages. The flowchart would then flow to a function block 270. It isnoted that if N is even at decision block 266, the program would flow tothe function block 270. Function block 270 is a function block wherein auser annually turns the output stack 180° without flipping the stack andthen puts it back in the drawer of the printer from which it came. Theprogram then flows to a decision block 74 to determine if the value of Nis even, and if so, to the function block 270 along the “Y” path toprint the pages 1, 3, 5, . . . N−1, and then to a decision block 278 todetermine if the value of N is odd. The program at this point will flowalong the “N” path to a N block 280. However, if the value of N isdetermined to be odd at decision block 274, the program will flowthrough the output of decision block 278 and to the input of a functionblock 282 which will print the pages 1, 3, 5, . . . N.

Referring now to FIG. 7, there is illustrated a flowchart depicting theduplex operation with a face down output, which is initiated at a block284 and then proceeds to a decision block 286 to determine if the valueof N is even. If so, the program then flows to a function block 288along the “Y” path to print the pages 2, 4, 6, . . . N. If it wasdetermined that the value of N is odd, the program would flow along an“N” path to a function block 290 to print the pages 2, 4, 6, . . . N−1.The program 288 would flow to a decision block 294, which determines ifN is odd and, if not, flows along a “N” path to the output of functionblock 290, the output of a decision block 294 is input to function block290. The output of function block 290 flows through a function block296, as well as the output along the “N” path of decision block 294.Decision block 296 indicates the manual operation wherein the user flipsthe output stack without turning it 180° and then inputs it back intothe drawer of the printer from which it was obtained. The program willthen flow to a decision block 298 to determine if the value of N iseven. If so, the program flows along a “Y” path to a function block 300and the pages 1, 3, 5, . . . N−1 and then to the input of a decisionblock 302. If the value of N is odd, the program flows along the “N”path from decision block 298 to the output of decision block 308 and toa function block 306 to print the pages 1, 3, 5, . . . N. The output ofthe decision block 302 along the “Y” path also flows to the functionblock 306 when N is even, and the flowchart flows along the “N” path toan “END” block 310, this being the path from the function block 306.

In summary, there has been provided a multiple print engineconfiguration wherein multiple jobs can be configured as a single printjob, transferred to a central distribution processor which parses theprint jobs into single pages and then determines how to pass them tomultiple print engines such that, when output therefrom are such thatwhen a user stacks them up from the output bin the order in which theprinters are arranged, or in any type of predetermined order, the pageswill be in a sequential manner as the print jobs were received.

Although the preferred embodiment has been described in detail, itshould be understood that various changes, substitutions and alterationscan be made therein without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. A multiple print engine system, comprising: atleast one work station for generating a print job having a plurality ofpages associated therewith; a RIP engine for receiving said print jobfrom said workstation and RIPing said print job to provide a RIPed printjob; a parsing device operating in conjunction with said RIP engine forparsing the RIPed print job to defined pages, the pages associated withthe print job; a page buffer for storing the RIPed pages in associationwith the printjob that they were generated in; a plurality of printersfor receiving one of the RIPed pages and printing the received RIPedpages and outputting them in an associated output bin; and a processorfor selectively distributing after RIPing all or a portion of said RIPedprint job by outputting select RIPed pages from said RIPed print jobstored in said page buffer for printing by select ones of said printersin a predetermined order for output as sheets in the associated outputbin.
 2. The multiple print engine system of claim 1, wherein there are aplurality of work stations provided, each for generating one or moreprint jobs for input to said RIP engine and a spooler disposed prior tosaid RIP engine for receiving said print jobs in parallel and outputtingsaid spooled print jobs serially to said RIP engine.
 3. The multipleprint engine system of claim 1, wherein said predetermined order is theorder of the copies in said print job, such that pages output from onesof said print engines, which print engines are arranged in apredetermined order, are in the order that they existed in the print jobwhen the sheets are stacked from the print engine order.
 4. The multipleprint engine of claim 1, wherein said page buffer comprises a singlepage buffer for storing all of said RIPed pages.
 5. The multiple printengine of claim 1, wherein the defined pages in said RIPed print jobcomprise a bit-mapped image of each of said pages in the original printjob.
 6. The multiple print engine of claim 1, wherein said RIP enginecomprises a single RIP engine.
 7. The multiple print engine of claim 6,wherein said RIP engine operates in a central processing unit and is asoftware-based RIP engine.
 8. The multiple print engine of claim 1, andfurther comprising a plurality of communication links, each of saidcommunication links disposed between said processor and one of saidplurality of printers, such that a separate communication path isprovided from said process or to each of said plurality of printers fortransmitting said RIPed pages thereacross.
 9. A multiple print enginesystem, comprising: at least a single work station for generating aprint job having a plurality of pages associated therewith anddesignated for a single print engine; a RIP engine for receiving saidprint job from said workstation and RIPing said print job to provide aRIPed print job; a parsing device operating in conjunction with said RIPengine for parsing the RIPed print job to define pages, the pagesassociated with the print job; a page buffer for storing RIPed pages forthe received print job; a plurality of printers for receiving one of theRIPed pages and printing the received RIPed pages and outputting them inan associated output bin; and a distributor for selectively distributingafter RIPing to a select one or ones of said printers all or a portionof said RIPed print job by outputting select RIPed pages from said RIPedprint job stored in said page buffer in an order determined by internalcriteria to said distributor and in accordance with aspects of saidprinters and independent of the designated printer information generatedby said at least one work station.
 10. The multiple print engine ofclaim 9, wherein the defined pages in said RIPed print job comprise abit-mapped image of each of said pages in the original print job. 11.The multiple print engine of claim 9, and further comprising a pluralityof communication links, each of said communication links disposedbetween said processor and one of said plurality of printers, such thata separate communication path is provided from said process or to eachof said plurality of printers for transmitting said RIPed pagesthereacross.
 12. The multiple print engine of claim 9, wherein said RIPengine comprises a single RIP engine.
 13. The multiple print engine ofclaim 12, wherein said RIP engine operates in a central processing unitand is a software-based RIP engine.
 14. The multiple print engine ofclaim 9, wherein said page buffer comprises a single page buffer forstoring all of said RIPed pages.
 15. A method for printing to multipleprint engines, comprising the steps of: providing at least one workstation for generating a print job having a plurality of pagesassociated therewith; receiving the print job from the workstation andRiPing the printjob with a RIP engine to provide a RIPed print job; inconjunction with the RIPing operation, parsing the RIPed print job todefined pages, the pages associated with the print job; storing in apage buffer the RIPed pages in association with the print job that theywere generated in; selectively distributing after RIPing all or aportion of the RIPed print job by outputting select RIPed pages fromsaid RIPed print job stored in said page buffer for printing by selectones of the printers in a predetermined order for output as sheets inthe associated output bin; and receiving one of the RIPed pages at theselect one of the printers and printing the received RIPed pages andoutputting them in an associated output bin.
 16. The method of claim 15,wherein there are a plurality of work stations provided, each forgenerating one or more print jobs for input to the RIP engine andfurther comprising the step of providing a spooler disposed prior to theRIP engine for receiving the print jobs in parallel and outputting thespooled print jobs serially to the RIP engine.
 17. The method of claim15, wherein the predetermined order is the order of the copies in theprint job, such that pages output from ones of the print engines, whichprint engines arc arranged in a predetermined order, are in the orderthat they existed in the print job when the sheets are stacked from theprint engine order.
 18. The method of claim 15, wherein the page buffercomprises a single page buffer for storing all of the RIPed pages. 19.The method of claim 15, wherein the defined pages in each of the RIPedprint job comprise a bit-mapped image of each of the pages in theoriginal print job.
 20. The method of claim 15, wherein the RIP enginecomprises a single RIP engine.
 21. The method of claim 20, wherein theRIP engine operates in a central processing unit and is a software-basedRIP engine.
 22. A method for printing to multiple print engines,comprising the steps of: providing at least a single work station forgenerating a print job having a plurality of pages associated therewithand designated for a select one of the print engines; receiving theprintjob from the workstation and RiPing the print job with a RIP engineto provide a RIPed print job in conjunction with the RIPing operation,parsing the RIPed print job to define pages, the pages associated withthe print job; storing in a page buffer the RIPed pages for the receivedprint job; receiving at the select one or ones of the printers thedistributed RIPed pages and printing the received RIPed pages andoutputting them in an associated output bin; selectively distributingafter RiPing to a select one or ones of the printers all or a portion ofthe RIPed print job by outputting select RIPed pages from the RIPedprint job stored in the page buffer in an order determined by criteriaassociated with the step of distributing and in accordance with aspectsof the printers and independent of the designated printer informationgenerated by the at least one work station; and receiving at the selectone or ones of the printers the distributed RIPed pages and printing thereceived RIPed pages and outputting them in an associated output bin.23. The method of claim 22, wherein the defined pages in the RIPed printjob comprise a bit-mapped image of each of the pages in the originalprint job.
 24. The method of claim 22, wherein the RIP engine comprisesa single RIP engine.
 25. The method of claim 24, wherein the RIP engineoperates in a central processing unit and is a software-based RIPengine.
 26. The method of claim 22, wherein the page buffer comprises asingle page buffer for storing all of the RIPed pages.